Servo-expanded brake



May 24, 1927. 1,629,532

E. P.- RENAUX sERvo EXPANDED BRAKE Original Filed March 14. 1923 m I 1 INVENTOR EUGEIgJ E F1 RENAUX' ATTORNEY Patented May 24,

UNITED .STAT-E'SJIPATENT iOFFlCE.

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This invention relates" to brakes and 1s illustrated as embodied in an nternal expanding' automobile An object of simple a servo inecha brake of this general character and pre er- 3 separate the servo shoe whlch s arranged co-axia'llyably including a the invention isto brake.

nism for operatin a drum eng g d by Y with respect to the brake drum, f In one desirable arrangement are arranged one inside the. sets of friction means 7 gage-able with the inside ofthe outer driun and one of whichis e side of the inner drum,

acts as a servo Preferably the shoes the two co-axial drums other with two one ngageable with-the outand or otherfriction means are expanded against the outer drum by a cam or the ing inwardly and engaged by a.

like having a radial arm-extend servo shoe operated by frictional engagement-with the outside of the inner drum. 7

Various features of novelty relate to the operation of the servo nected spaced applying porting the servo shoe springs connected to the'outer brake devices-and to supby means of return shoes.

The advantages of theseconstructions and various additional-features of novelt desirable particular constructions will parent from the followin illustrative embodiment s own in the accom panying drawings, in which Figure l is a vertical section through the brakejust inside the head of the brake drums;

Fi re 2 is a the'hne 22 of artial vertical section on igure 1, and showing the relation of the two drums.

The illustrated brakeincludes an inner drum 10 and an outer drum 12 shown insame such as a The friction means which engages the i r 1,-. i-negarded as divid d from my prior applicaside of the outer drum 12 may head 14 andboth of their open sides by a backing plate 16.

be a pair of shoes 18 and 20 anchored at the bottom of the drum by being mounted on ried bv the backing plate 16.

pivots 22 carhe upper or double cam 26 carrie d-by a spindle 28 jourward.

surface-0t the inner with a notch operatively embracing a proof which is y entage'ously one of which device to operate the other.

shoe by inter-conand;

description of one 192a, Serial 116,625,072. Trivium and this application filed April s, 1926 ]Seria1 no. 10am,

nalledi'in the backing plate 16 and having an operating arm 30 projecting radially inof'theshoes 18 andf20 there is arranged a servo shoe 32=,engageable' with the outside drum 10 and formed jectionxi on the inner end of the lever 30 so that movement'of-the servo shoe 32 in either direction with drum 1() rocksthe lever 30 to force shoes 18- and 20 apart against the drum '12. The servo shoe 32 may advanbesupported at its opposite ends by a pair of radial springs 36 connecting it to the adjacent parts of the shoes 18 and 20 and which not only support the servo shoe but serve also as return springs urgingit- The servo shoe away from the drum 10.

42 may be forced against the drum 1( by novel inter-connected applying devices such as rollers 38 carried by crank arms 40 and.

operatively connected byinter-meshing gear or rack segments 42 and rocked by an arm 44 operated by the usual brake-operating connections 46.

When the brake is applied the rollers 38 permit the shoe 32 to shitt a substantial distance lengthwlse or circumferentially of the drum 10 in one direction or the other to apply the shoes 18 and 20. When the brake is released the springs 36 immediately pull the shoe 32 away from the drum 10 while the spring 24 has the I double function of pulling the shoes 18 and 20 away from the drum and swin turn the shoe 32 to its central or initial position.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that particular embodiment or otherwise than by the terms of the appended claims. Most of the subject-matter erein claimed is to be tion No. 625,072, filed March 14, 1923.

I claim: r

1. A brake comprising, in combination, a pair of substantially co-axial; drums arranged one within the other, friction means engageable with the inner surface ofthe outer drum, and a servo shoe engageable with the outer surface of the inner drum and operable to force the friction means against the outer drum.

2. A brake comprising, in combination, a pair of co-axial drums arrangedone within the other, friction means expansible against the inner surface of the outer drum, friction means engageabie with the outer surface of the inner drum, and connections operated by one of said means to operate the other of said means.

3. A brake comprising, in combination, a pair of coaxial drums, a friction device expansible against the inner surface of the outer drum and having adjacent free ends,

a servo shoe engageable with the outer surface of the inner drum, and an expanding device engaging said free ends and having an o crating arm extending substantially radial 0f the drums and engaged by the servo s cc.

4. A brake comprising, in combination, a pair of co-axial drums, expansible friction means engageable with the inner surface of the outer drum and formed with adjacent ree ends, a servo shoe engageable with the outer surface of the inner drum, a cam en-' gaging said adjacent free ends, and an operating arm for the cam extending substantially radially inward of the drum and engaged by said servo shoe.

5.. A brake comprising, in combination, a pair ofv substantially co-axial drums, shoes engageable with the inner surface of the outer drum and having adjacent free ends, a servo shoe opposite said free ends engageable with the outer surface of the inner drum and arranged to force said shoes apart against the outer drum, and springs connecting the ends of the servo shoe to the pair of shoes and urging the servo shoe away from the inner drum.

6. A brake comprising, in combination, a pair of co-axial drums, friction means engageable with the inside of the outside drum, a servo shoe engageable With the outside of the inner drum and arranged to expand EUGENE PROSPER REN AUX. 

